Process of manufacturing sugar



UNITED STATES PATENT OFFICE.

()T'lO A. BIELMANN, OF AMESVILLE, LOUISIANA.

PROCESS OF MANUFACTURING SUGAR.

SPECIFICATION forming part of Letters Patent No. 557,642 dated April 7,1896. Application filed July 21, 1894. Serial No. 518,202. (No specimensd State of Louisiana, have invented certain new and useful Improvements in Processes of Manufacturing Sugar; and I do hereby declare that the following is a full, clear, and

exact description of the same.

Myinvention relates to the process of manufacturing sugar direct from sugar-cane, beets, or sorghum or from any solution containing sucrose, the purpose thereof being to obtain a high-grade sugar suitable for direct consumption and to reduce the proportion of what are termed second and third sugars or, as they are sometimes called, soft sugars or after-products.

It is my purpose also to simplify and improve the processes in common use without entailing the costly installations required with other processes; to reduce the quantity of apparatus, fuel, and labor used heretofore in the manufacture of sugar by recoverin g in high-grade sugar in one continuous operation a greater proportion of the crystallizable sugar contained in any given sugar solution than has heretofore been practicable, and to provide a process of manufacture by which all of the available crystallizable sugar is obtained by a continuous operation, avoiding the necessity of repeated shutting down and starting up of factories on plantations, as has been usual heretofore, to recover the seconds and thirds or after-products. 4

My invention consists, to these ends, in the art, process, or mode of procedure hereinafter fully explained, and then particularly pointed out and defined in the claims.

In order that those skilled in the art to which my said invention-pertains may full-y understand and be ablete practice the same, I will now describe said invention in detail, begin ning at that point in the usual process of manufacture at which my invention is introduced.

Premising that by the term purity coefficient is meant the percentage of sucrose contained in a given quantity of masse-cuite, in order to illustrate what is accomplished by my invention and to aid in distinguishing the same from prior methods I will-mentionat the outset that in every strike of massein the parish of Jefferson and cuite there is a certain relation between the yield in dry sugar and the purity coefiiciont of the sugar solution from which the strike is made, which, each strike containing the same number of pounds of massecuite, may

be represented substantially as follows: Fifty thousand pounds of first masse-cuite made from a sugar solution of the purity coeiiieient;

of seventy-five yields twenty-live thousand pounds of dry sugar. Fifty thousand pounds of second masse-ouite-made from a sugar solution having a purity-coefiicient flifty-five, which is derived from the uucrystallized part of the first masse-cuite,yields twelve thousand five hundred poundsof dry sugar. Fifty thousand poun ls of third luasse-cuitemade from a sugar solution of ,the purity coefficient of thirty-five, which is derived from the uncrystollized part-of the secondinasse-euitayields six thousand two hundred and fifty pounds of dry sugar, &c. These figures, though not absolutely correct, are approximately so, and serve to illustrate that second masse-cuite made from a sugar solution of the purity coefficient of'55, which is twenty points lower than the purity eoefficient of the solution from which the first masse-cuite is made, yields only fifty per centfiof the quantity of dry sugar yielded by first masse-cuite. The same proportionate diminution in yield of dry sugarobtaius in the third niasse-cuitc, which is made from a sugar solution of the purity coefficient of 35, which is twen ty points lower than the purity coefiicient of the solution from which the second inasse-cuite is made The decreased yields between first, second, and third masse-cuite is attributable to the decreased purity coefiicient of the solutions from which they are made, which is caused by the removal in each operation of the pro-- portion of sucrose recovered in the dry sugar obtained and the consequent increase in the proportion of non-sugars of both organic and inorganic character contained in the original solution, as well as' additional non-sugars which are created in the course of each operation ofreboiling Toovercome the-diiliculties of crystallization that present themselves on account of the decrease in the purity coelfioient of each succeeding solution,-I reduce by dilution the,

solution derived from the uucrystallized partof thefirst massescuite, and in turn the solution derived from. the uncrysl'allized part ol:' the second lJLda$U-('lllllC, and so on to as low a density as circumstances justifysay bccrystals being, for example, one-eighth ol one tween 3 and 2 l liaum--becausc oi the fact that all crystallized impurities formed by the 1 crease the grainin e capacity oi? the solulil-in.

treatment hereinafter described ot a higher specific gravity than the specific gravityof the solution containing them will settle to the bottom of the vessel, while otherwise they would remain suspended in the solution. Having reduced the solution to the desired density, 1 add a suitable alkali or alkaline earth in excess, either in the form of carbonate or hyd rate, the object being to render the solution distinctly alkaline in order to eliminate or condor less obnoxious the non-sugars present. llcat being now applied the solution is brought to a temperature alittle below the boiling-point, or to about 300 Fahrenheit, which causes the lighter impurities to rise and form a scum on the top of the solution, which is removed in the usual manner. This being done, I add to the remaining, solution enough of any diluted acid to render the sugar solution neutral-such, for example, as phosphoric acid-and again apply heat to cause thorough mixing, whereby the heavier impurities are caused to settle to the bottom of the Vcsselin which the heating is done, which heavier impurities are removed by any desirable process, either by filtration of the solution or by decanting the clear liquid. This treated solution is now ready to be reboiled and evaporated to the point of crystallization in the vacuum-pan.

There is, as l have heretofore indicated, a certain definite relation between the purity cocfiicient and the yield or quantity of dry sugar produced from any given sugar solution. As the former increases the latter is similarly increased, and for the purposes of this description I speak of this relation be tween the yield and the purity coefficient as the graining capacity.

The second part of my process consists in the use of sugar crystals, either dry or wet, ol'f difi'erent-sized grains, with each of the several sugar solutions liQPOllllQQfOlC 'lescribcd, in order to artificially increase the graining capacity of each In PateutNo'. 38G,l.l58,grantcd to me in 185's,

1 have describcd'the use of sugar crystals tor imy'iroving the granulai ion of such r sol ul ions. Since that patent was issued to me i have elaborated this process, of which the follow ing is a full description.

To illustrate: To a strike oi litty thousand pounds of second niassc-cuitc made from a solution of the purity cocl'licicni of 1- I use, as hereinafterdescribed, about ten per cent. oi its weight or five thousand pounds of sugar crystals, (eithcrin adry or wet: sl.atc,)lhc average size of which crystals being, as an example, one-quarter of a millimeter in length to inoreasc the gra-ining capacity of the solution. To a strike of fifty thousand pounds of third masse-cuite made from a solution of the pnrity cocllieiont oi. 35 I use in the same way about ten per cent. or live thousand poundsof sugar crystals, the average size of, \Ylllvli millimeter-in length, which naturally will ill-- basing the calculation of graining capacity upon the amount of urea presented by the different-sized crystals for the deposit of the sugar molecules (remained in each solution. Upon the principle that the total area oi sin face presented by a sugar crystal having a length of one-eighth of one mill imcter is about one-half of the total area of a crystal having alength of onequarterof one millimeter live thousand pounds of the small crystals will present an area about twice as great as live thousand poundsof the larger crystals would, since it takes eight crystals oi the smaller dimensions tomakc onccry. alol' thelargcr di' mensions. \Vcre suga r crystals pericctculns, this would be the exact measure of the difference in area of the two six cited. The objcct in using the diilierent s .cs of sugar crys tals is to present a greater area upon which the sugar molecules may be deposited in a sugar solution of low purity than in one possessing a high purity.

Sugar crystals of the l'Cllllll'Q l size may be obtained-by boiling strikes oi second massecuite in the ordinary way to different densities, the crystals being smaller as the densiiy increases. The larger crystals can easily be brought to the desired size by mixing the dry crystals which are too large for the intended purpose with an unsaiiu-ated sugar solution. The unsaturated solution, having, for instance, a dcnsity oi'f l5 llrix, will di minish and reduce the sugar crystals to the size desired for use in a. strike having a purity eoellicimit corresponding lhcrewilh, which ellect can easily be (,ibscrvcd by the use of a llllClOSL'OPU, and can be regulated by the use of more or less of the sugar solution to the given amoi at of sugar-crystals. 'l'his mixing oi the ugar c yslals uilh uusuluiu'rted sugar-solutions in. order to diminish them to the desired size may be done in any snil able vessel, but l prefer to do it in a small tank, the bottom of \\'l)l( '.l (lil 'lll lUlHfllllLYlllfl than the bottom of the vacuumu in order to lncililnic the introduction into the pin.

The solution derived l'rom the unory dulllvzcd part olf lirsl. liliViil'J'tfllllt', nl'lcr hating een diluted and treated ;i7- dosr-riln-d, drawn into the :icuunr-pun and boiled down to about li llnunu'r. 'lhcu the sugar rrysluls, having a length, for emimplo, oi aloud -one-quarterolfn iniliiinclcr,:n'e brought into in pan by any suitable arrangement, care This icing taken not to melt the cryslals.

r strike, being made from a soiulhin derived from the uinxryslallizcd part of lirsl. mass-(r cuitcgis now boiled and linislu-d like a strike of original lirsl mnssedruitc.

The sugar crystals used being nuclei upon which the crystnllinable part of lhe solution cuite, if the purity coefficient should be too low to make the sugar crystals grow in the vacuum-pan, the modus opcrao'zd'i has to be changed. I fill the pan in the regular way to about two-thirds of its capacity with massecuite having a density of about 42 Baum, when I introduceinto the pan the sugar crystals of the smaller size mentioned and finish the strike as usual, only taking care not to melt the crystals. This strike, which is third masse-cuite, goes into wagons or tanks and is put into the hot room; but instead of having to remain there for months, as is required by the ordinary process, it will be ready for drying in three weeks and will produce a sugar of well-developed grain, and the molasses from it under normal conditions is practically exhausted; Analysis of this molasses will show that the purity is about from ten to twenty per cent. lower than obtainable by the most skilful manipulation by the ordinary process-that is to say, after the crystals of the last strike of this kind of massecuite are dried I close the factory, leaving no material whatever for further operations until next crop commences;

It is not possible to state with absolute accuracy the diameters of the different sizes of sugar crystals used in strikes having different purity coefiicients. These dimensions can only be given approximately. For example, in a strike of masse-euite having a purity coefiicient or percentage of sucrose of 55 I use about ten per cent. of its weight of sugar crystals having an average length of one-quarter of a millimeter or thereabout. In a strike made from a solution having a purity coefiieient of 35 I use about ten per cent. of sugar crystals having a length of oneeighth of a millimeter or thereabout. If these dimensions are subtantially observed, the results I claim will be obtained; but of course I may vary the dimensions named within certain limits without departing from my invention. In like manner I do not confine myself to the use of ten per cent, by weight, of sugar crystals, as described, for the quantity may be varied, although I regard the proportions named as preferable.

What I claim is-- 1. In the manufacture of sugar, the process herein described for obtaining a greater yield and better quality of high-grade sugar from a given amount of. sugar-con taining solution, said process consisting in adding to the uncrystallized part of a first, second or third masse-cuite, a suitable proportion, as for example, ten per cent. by weight, of sugar crystals of a length substantially proportioned to the purity coefiic'ient of said solution, for example, a length of one-quarter of a millimeter in a sugar-containing solution having a pnrity coefficient of 55-}; millimeters in a solution having a purity coefiicient of 35, or thereabout, substantially as described.

2. In the manufacture of sugar, the process described which consists in adding to a sugarcontaining solution previously reduced to a density of between 25 and 35 Baum, whereby the impurities of higher specific gravity are caused to settle, an alkaline earth in excess, to render the solution distinctly alkaline and to eliminate or render less obnoxious the non-sugar present, then applying heat to cause the lighter impurities to rise and enable them to be removed by skimming, adding a suitable acid, such as phosphoric acid, to render the solution neutral, again heating and thoroughly mixin g the solution and the added ingredients to precipitate the heavier impurities, and finally separating the latter in any suitable manner, substantially as described.

.In the manufacture of sugar, the process hereinbefore described, which consists in re ducing sugar crystals to a size or diameter adapted -to a sugar solution of a given purity coefiicient, said process consisting in the mixing of said sugar crystals with an unsaturated sugar solution in order to reduce the said crystals to the required size, said unsaturated sugar solution having a density for example of 45 Brix, and finally adding said crystals to the unerystallized part of a strike of massecuite having a corresponding purity coeflicient, or thereabout, to promote the graining capacity and expedite the process of crystallization, substantially as described.

4. In the manufacture of sugar, the process described, which consists in diluting the uncrystallized part derived from afirst orsecond masse-cuite to a low density to aid in eliminating the heavier impurities which have a higher specific gravity than the diluted solution, adding an alkali, or alkaline earth in excess to render said solution distinctly alkaline and to eliminate or render less obnoxious the non-su gar present, then heating to a point below boiling to cause the lighter impurities to rise, removing said impurities, then adding an acid to render the solution neutral, again heating to cause thorough mixture and 7 cause the heavier impurities to settle, removing the latter, and then evaporating to erys:

tallization, substantially as described.

In testimony whereof I have hereunto subscribed my name in the presence of two witnesses.

OTTO A. MELMANN.

Witnesses:

WAL'IER II. COOK, Rom. E. Runs. 

